Risks of all-cause death and completed suicide in patients with schizophrenia/schizoaffective disorder treated with long-acting injectable or oral antipsychotics: A population-based retrospective cohort study in Taiwan

Background: Long-acting injectable (LAI) antipsychotics improve medication adherence in patients with schizophrenia and provide an extended duration of therapeutic drug levels but with administration of an increased dose. Real-world mortality data in patients prescribed LAIs are lacking. We conducted a population-based cohort study to estimate and compare the incidence rates of all-cause death and completed suicide in patients with schizophrenia/schizoaffective disorder exposed to LAIs and oral antipsychotics. Methods: Patients with a diagnosis of schizophrenia/schizoaffective disorder between 01-Jan- 2015 and 30-Nov-2019 were enrolled from the Taiwan National Health Insurance Research Database and linked to Death Registry records. Eligible patients were new antipsychotic users. Relative risks of death for each antipsychotic in comparison with oral paliperidone were evaluated using a Cox proportional hazard model adjusted for age, sex, Charlson Co-morbidity Index, index year, bipolar or major depressive or other mood disorders, and mental disorders due to drug use, and frequency of hospitalization during the baseline period. Results: There were 228,791.08 person-years of follow-up (mean follow up time 2.48 years ). The incidence rate of all-cause death in users of LAI paliperidone administered monthly (PP1M) and every 3 months (PP3M) was 7.40 per 1000 person-years (95% confidence interval 5.94-9.11) and 9.93 (5.88-15.79), respectively. The incidence of completed suicide was 2.03 per 1000 person-years (1.32-2.99), and 3.10 (1.14-6.88), respectively. No significant associations were observed between PP1M or PP3M compared to oral paliperidone in terms of the incidence of all50 cause death or for completed suicide. Discussion: No increased risk of all-cause death or completed suicide was observed in users of antipsychotics LAIs, including PP1M and PP3M.